class AddCourseidToNews < ActiveRecord::Migration #迁移原课程通知数据 def change add_column :news, :course_id, :int # course_id不能直接设置为 project_id #News.where('project_id IN (SELECT id FROM projects WHERE project_type=1)').update_all("course_id = project_id") #News.where('project_id IN (SELECT id FROM projects WHERE project_type=1)').update_all(project_id: -1) News.all.each do |news| project = Project.find_by_id(news.project_id) if project && project.project_type == 1 news.course_id = project.course_extra.id news.project_id = -1 news.save(:validate => false) end end end end